FLEXOR TENDON HEALING

每年，美国有超过300，000例上肢损伤需要手术治疗，以修复中间物质或插入部位受伤的肌腱。 据估计，这些伤害造成400万个工作日的损失。 屈肌腱中间体损伤的治疗的最新进展是由修复和康复变量的科学理解的进步驱动的。 相比之下，几十年来屈肌腱附着点损伤的治疗没有显著变化，部分原因是很少有科学研究支持这种变化。 因此，许多患者在屈肌腱附着点修复后的临床结果较差，表现为活动范围减少和握力丧失。 我们的长期目标是确定修复和康复技术，将持续产生良好的临床功能，即时和延迟治疗屈肌腱附着点损伤。 在本项目中，我们将应用犬屈肌腱止点损伤和修复模型，以研究先前未提及的几个临床相关变量：1）肌腱与骨重新连接的缝合技术，2）康复期间应用的肌腱力和偏移增加，3）损伤至修复的时间间隔，以及4）肌腱-骨愈合的生长因子增强。 我们的主要假设是修复部位的刚度和强度通过在早期被动运动康复期间应用增加的肌腱力而得到改善。 此外，我们假设肌腱-骨修复部位的愈合可以通过在修复时递送靶向基因产物来加速，所述靶向基因产物增强对早期组织愈合重要的生长因子的表达。这些包括：碱性成纤维细胞生长因子（bFGF）、血小板衍生生长因子（PDGF）和血管内皮生长因子（VEGF）。 将采用多学科方法评价实验变量，并分析生物力学、组织学和生化结果。 实际受益的最终确定将基于关键的前6周愈合期间手指活动度和修复部位刚度和强度的生物力学评估。识别改进的插入部位损伤的修复和康复技术将是实现临床治疗现代化和改善患者预后的第一步。

Annually, more than 300,000 upper extremity injuries in the U.S. require operative treatment for repair of tendons injured in their midsubstance or at their insertion sites. These injuries lead to an estimated loss of 4 million workdays. Recent improvements in the treatment of flexor tendon midsubstance injuries have been driven by advances in the scientific understanding of repair and rehabilitation variables. By contrast, there have been no significant changes in the treatment of flexor tendon insertion-site injuries in several decades, in part because there have been few scientific investigations to support such changes. As a result, many patients have a poor clinical outcome after repair of the flexor tendon insertion site, as evidenced by decreased range of motion and loss of grip strength. Our long-term objective is to identify repair and rehabilitation techniques that will consistently produce excellent clinical function for immediate and delayed treatment of flexor tendon insertion-site injuries. In this project, we will apply a canine model of flexor tendon insertion-site injury and repair to investigate several clinically relevant variables that have not been previously addressed: 1) suture technique for reattachment of tendon to bone, 2) increased tendon force and excursion applied during rehabilitation, 3) time interval from injury to repair, and 4) growth factor enhancement of tendon-bone healing. Our primary hypothesis is that the stiffness and strength of the repair site are improved by application of increased tendon force during early, passive motion rehabilitation. In addition, we hypothesize that healing of the tendon-bone repair site can be accelerated by delivery, at the time of repair, of targeted gene products that enhance expression of growth factors that are important to early tissue healing. These include: basic fibroblast growth factor (bFGF), platelet- derived growth factor (PDGF) and vascular endothelial growth factor (VEGF). A multidisciplinary approach will be utilized for evaluation of the experimental variables, with biomechanical, histological and biochemical outcomes analyzed. The final determination of practical benefit will be based on biomechanical assessment of digital range of motion and repair-site stiffness and strength during the critical first 6 weeks of healing. Identification of improved repair and rehabilitation techniques for insertion-site injuries will be an initial step toward modernizing clinical treatment and improving patient outcomes.